I am new to the 5.7 pistol. I really like the way it shoots. I also find it very comfortable to carry IWB. But I'm undecided what round to use in Self Defense. I'm really leaning towards a frangible round of some kind , but which? I'm not sure. I would like to add I prefer to reload my own rounds.
Bazz

They're all about the same question
There is no one 'best' round. What do need it to do? Are you worried about BGs in body armor? Are you worried about over penetration? Etc...
If the threads linked above can't answer your question, they can help you ask the right question(s).

Also, using reloads for self defense may pose legal hazards in the event you do have to defend yourself. Suggest you delve into that before you dive in.

Also, using reloads for self defense may pose legal hazards in the event you do have to defend yourself.

Yep, I have read through all of those threads, but they all pretty well recommend using Elite Ammunition , problem with EA is you can't actually buy any, I know cause I've just had my order cancelled. Besides, I would like to reload. I can't see any legal reason why I should use a reload to shoot a,villain rather than a factory load. EA is a reloader, not OEM correct?
A dead,villain is a dead villain regardless of bullet type. Surely if it's legal to own it's legal to use.
Baz

I miss Quaker Oats. Most breakfast cereals have too much sugar, though.

Everything is so fake, these days. I was happy to find an alternative to Milk, because I could drink more of it. Then, I found out Almond milk is just water + thickening agents + vitamin powder with 3% almonds. 3%. Basically an ounce per carton. I was just discussing this 5 minutes ago with a friend.

What a disappointment.

I don't think the frangible round has been honed for SD purposes, in the 5.7x28mm caliber, yet. The .223/.224 versions are a tad too heavy to really lean on the velocity-advantage of the caliber, and the ones that were made by Sinterfire in the past were too brittle. I had a box of unloaded ones, and one of them already had a chip in it.

I am eager to search for the FN factory frangible... only to observe and learn how much more rigid/brittle the compound they use to make the bullet is, compared to Sinterfire. I doubt their round is purposed for SD. It's most probably for training purposes.

Most frangible rounds do not penetrate deeply (enough) and only have shallow cavaties (albeit devastating). Perhaps that is the mantra of why most mfg's stay away from spending too much effort in engineering a frangible round for the SD role.

Just some musings...

Never attribute to malice that which can be explained by stupidity.
The shooter will always matter more than the gear ever will.
Stop relying on others to do the work for you.
Shoot more, worry less.

It would seem that you really don't need a lot of penetration when using a frangible . For example, the DRT with its Fletch arrow arrangement , after penetration of the chest wall, in a COM shot, is all that's required, after that the Fletch arrows go off in every direction inflicting instant and massive organ . The same applies to the skull. Both scenarios, if true, would surely result in a "one shot kill" and instant disablement of the BG. This is the case with a 12 gauge loaded with buckshot. Well more or less.

I'm not sure any of this matters. The shooter in the Fort Hood shootings used 197 mostly. It was very effective in so much he was not tackled by anyone in the building. All would be defenders were stopped in their tracks. So maybe I'll just stick to 40gr V-Max

Frangible is completely different than Fragmenting, and I had an assumption that you were alluding to Fragmenting, instead.

In which case... most FsN rounds with jackets... and perhaps many without, fragment.

So....

The real answer is; the best SD round is the one you can place in COM. In other words, you're asking the wrong question. The question you should place is, "How can I become a better and more efficient/proficient marksman?"

If ss197, the weakest factory round, can do the job... then it isn't the round, is it? It's the shooter.

"The shooter will always matter more than the gear ever will."

Never attribute to malice that which can be explained by stupidity.
The shooter will always matter more than the gear ever will.
Stop relying on others to do the work for you.
Shoot more, worry less.

Respectfully, I disagree, being a great marksman does not mean your good at self defense, it means you can accurately hit a paper target. Your self defense skills need to be reactive and not rely on much thinking time or time to take careful aim. Neither is COM the best way to neutralize a BG, a head shot or two is certain to result in instant disablement. At least that was what I was taught. A high velocity "armor piecing" bullet is likely as not disable a BG instantly , whereas a Fragmenting bullet to the head will do the job nicely. It will also certainly work well I a upper torso shot. True, a ss190 round hitting bone will certainly shatter it, possibly the best place for this round is the leg or pelvis. It's very hard to stand on a leg with a shattered femur or pelvis.
Since the 5.7 has a good large mag, then alternating rounds or SS 190 and SS 197 might be in order. If all else fails, I always carry a combat knife and know how to use it!

It's long, and if it tumbles, it cuts a wide path. I think they're supposed to tumble, but I don't know if they really do. I think of it in terms of the 5.56. The 193 and 855 are shortish, bad guys in the desert are skinny, so they poke nice, neat holes in them. The 262 is longish, and slower, and tumbles early. It rips wide holes in them.